In the present study, hydraulic and thermal performances of nano-enhanced drilling muds have been studied across the complex geometry of a rotating polycrystalline diamond compact (PDC) drill bit using computational fluid dynamics techniques. Toward this goal, a robust converging procedure is applied to generate an advanced tetrahedral/prism grid structure using special techniques. We also utilize a combination of the realizable k-ԑ turbulence model with enhanced wall treatment and Eulerian-Lagrangian discrete phase model (DPM) to investigate the flow field and particles tracking across the bit. The results reveal that the rheological properties enhancement obtained by adding even a small quantity of nano-fluids leads to a remarkable increase in the cutting transport efficiency. According to our results, CuO and ZnO nano-enhanced muds show up to 127% and a 68% rise over the cutting transport ratio of the base fluid at the bit rotational speed of 30 rpm. Besides, the predicted temperature on tip of the bit cutters indicates that increasing the thermal conductivity of nano-enhanced muds can lead to effective cooling only in conjunction with improving rheological characteristics. CuO NWBMs show up to a 16.7% reduction in the temperature of the front surface of bit cutters over the base fluid.

在本研究中，已经使用计算流体动力学技术在旋转多晶金刚石复合片 (PDC) 钻头的复杂几何形状中研究了纳米增强钻井泥浆的水力和热性能。为实现这一目标，应用了强大的收敛程序，以使用特殊技术生成先进的四面体/棱镜网格结构。我们还利用可实现的 k-ԑ 湍流模型与增强壁处理和欧拉-拉格朗日离散相模型 (DPM) 的组合来研究流场和穿过钻头的粒子跟踪。结果表明，即使添加少量纳米流体，流变性能的增强也会导致切割传输效率的显着提高。根据我们的结果，在钻头转速为 30 rpm 时，CuO 和 ZnO 纳米增强泥浆比基础液的切削输送率提高了 127% 和 68%。此外，对刀尖温度的预测表明，提高纳米增强泥浆的热导率只有在改善流变特性的同时才能实现有效冷却。CuO NWBM 表明，在基液上，钻头刀具前表面的温度降低了 16.7%。